DobermanDad

hahahahahaha!

They have so much stuff I want.

I'm probably going to order those bushings and brace.

ThomasC2

Mr Alex, are your tie rods up to date? They are much more import than those bushings.

Thomas

Vandit

Read post #5

LPMM

QQ... If you order the Rothsport reinforcement, it comes with the appropriate longer bolts. Why the need for the 2 additional bolts as shown in the Technical Bulletin?

Mr.Alex

I think with the way our supports are designed, solid mounts might grind away into the steering rack over time.

Will do. This right here so far is the most informative post I was able to dig up on swapping them.

https://rennlist.com/forums/993-foru...l#post11702448

Part # wise.
OEM Rubber Bushings: 964-347-137-07
OEM Bolts (without brace) : 999-218-102-01 Pan-Head Screw M 8 X 60
Washers: 900-031-105-01

I was under assumption the there are two different lengths for the bolts based on how the clamp/clip around the bushing is, but autoatlanta lists the same length for all four bolts. Unless you get the brace which comes with the already longer ones.

Swapped both tie rods last year. Inner joints too. Old ones were well worn.

I believe that Vandit is just confirming that out of the four bolts, two are different lengths, and its recommended to replace all bolts and washers when doings this.

LPMM

10-4.

RSAErick

I'm on a quest to replace every single part on my 964 one-by-one with new parts, in an attempt to keep my cost of ownership higher that the 'value' of the car (I'm succeeding, despite the best efforts of the market). Therefore, I naturally considered replacing the steering rack bushings when I did my suspension refresh/upgrade. However, upon inspection, it didn't seem that these bushing saw the movement-related wear that the other rubber components in the suspension see. As such, they didn't appear to be 'worn' - at least to the point that would make any perceivable difference in the performance or feel of the car. Maybe I'm wrong about that, and I'm expecting that someone will soon chime in about a 15% increase in hp, which will force me to take action. But until then, I find myself in an unusual (and unpopular) role of not upgrading.

Goughary

Steering rack bushings, if they are the right density poly. And blue, not the red ones. Bright royal blue...they give you a 15.35% increase in hp, but only under lateral loads when you are using 20" wheels. 17-18" wheels will only yield a 13.72% hp increase due to the diameter decrease in over-all diameter. C4's unfortunately can't benefit from this as they can't utilize the 20" wheel upgrade bolts in the ti spindles from that other post. You know the one...

Greg_V

you forgot the 31.415 ft-lb boost in torque that the kevlar gives. Only if have a kevlar heater-bypass tube though. Doesn't show up on the dyno with a carbon tube for some reason.

PhatPhlatSix

Also to get the best performance, it is important to do things that give you an additive power value first, e.g. +10bhp. You then do the mods that give you percentage increase, e.g. for 10% increase in power you multiply by 1.1, so if you have done the additive mod first, the multiplier gives you the extra benefit.

So if a set of plug leads gives you +8bhp and an exhaust bypass 10% increase, the order that you do the mods would work at as:

(250 + 8) * 1.1 = 283.8bhp, or
(250 * 1.1) + 8 = 283 bhp

A small difference, but if you are racing and every little bit counts, it could be very important.

DobermanDad

LOL!

Well, if you gotta replace the old bushings you might as well upgrade.

-nick

Resurrecting this thread-

I replaced my old, squishy, rubber steering rack mounts with the poly ones last weekend. The difference is subtle, but the steering is indeed a bit more responsive for street driving. Back to back a/x this weekend and I'm expecting that the better response will help. Certainly can't hurt.

Took as long to raise the front end and settle it on jack stands as it did to replace the bushings. Very easy. Remove the front underbody tray (buy some new $0.10 plastic nuts while you're at it). Remove the 4x allen/hex bolts that mount the rack to the crossmember. Tug the old bushings out and squeeze the new ones in. Thread the hex bolts back in gently as to not cross-thread into the aluminum threads. I put in the long bolts on each side first, tighten those up a bit, then thread in the short bolts. Final torque is 33 lbs. As Vandit mentioned, the bushings squish as you tighten the bolts and it feels a lot like you're stripping the threads as they tighten up. I may go back and re-torque next week in case they settled into place.

Mind, I've had my rack out recently and everything is new. The first time that I removed the the rack, the steel allen/hex mounting bolts had corroded into the alloy mounts (car is not afraid of snow). Two bolts sheared, and only came out after removing the crossmember, soaking in penetrating oil, then adding heat. I had to replace both alloy clamps and all of the bolts. Made sure to heavily coat everything with anti-seize for reinstallation.

I got the bushings from "dijia" on ebay for $27 shipped. Shame on Rothsport for price gouging- $39 and they won't tell you how much you pay for shipping until after you order. Porsche tax indeed...

Goughary

Did you install the rack brace as well?

DobermanDad

I wish I would have installed that rack brace when I did mine. Don't know why I forgot about getting one.

Is that brace going to add any benefits if you're not running 18s?

Goughary

Yes. The rack is sloppy. And anything to firm it up will help. Granted, in reality we aren't trying to gain a few tenths in a lap time when driving on the street. But, for a bit of improved feel on the street I think it's worth it since it's so easy and inexpensive to do. Think about it....Porsche added it for the 993...why? Because they realized they got it wrong on the 964....